707 1. 1 aircraft cfg.  fuel_flow scalar=1.45  by CS

464 NM  my totat fuel used: 38000 Lbs (???)
Average  four flights Cruise Fuel/hour used: 20,000Lbs (Fl300)
Average IA speed/hour :  300 knots

727-100  aircraft cfg.  fuel_flow_ scalar=0.361 (?)  setting by CS

Is there some thing wrong with 707 1.1  "Fuel_flow scalar" settings :-/

The worst case scenario at FL290 would be (according to this table)

http://img63.imageshack.us/img63/8285/worstcase.th.jpg

GW 315.000, cruising Alt 29.000, OAT +20 ISA

494 kts : (31,3 : 1000) = 15.783 lbs/hour

So the short answer to your question would be "yes" and the longer one "at least unrealistic" if your fuel consumption was observed right.
I haven't checked myself so far I must admit.

But I doubt that you were flying that heavy and I suggest to measure the average speed in a GS value or to go with mach numbers then.

See those shaded numbers there? These are the altitudes to aim for according to your GW. So FL300 is too low for her at every given flyable GW. FL330 to 410 is the range to be recommended.

Lets see if this makes a big difference then.

Thanks for your reply. I will make 7 hours test fly and will capture the fuel figures.

If my previous figures were right I will not make  my destination Frankfurt. Maybe, if I am lucky Keflavik  shores.. :D

BTW why  much difference between 727 and 707 engine_flow_scalar?

I forgot to say. I will use your chart for this fly. :)

asanal wrote on Oct 12^th, 2010 at 7:13pm:

Thanks for your reply. I will make 7 hours test fly and will capture the fuel figures. If my previous figures were right I will not make  my destination Frankfurt. Maybe, if I am lucky Keflavik  shores.. :D BTW why  much difference between 727 and 707 engine_flow_scalar?

You should be fine for a 7 hour flight. My last one was a 8 hour flight with about 95% fuel, and I had about 20'000lbs left after landing.  ;) Fly high and keep the fuel-flow down.

asanal wrote on Oct 12^th, 2010 at 7:15pm:

I forgot to say. I will use your chart for this fly. :)

Oh it's not my chart, asanal. Just search for "707perf.zip" at Avsim and find more useful stuff there.

I did a flight at FL320-FL340 (I didn't have the charts that CoolP mentions) in the 707 from YMML (Melbourne, Australia) - NFFN (Nadi, Fiji). A distance of 2092 nm. It took 5 hours and 50 minutes. I took off with 60% (95906.2 lbs) fuel and landed with 28% (45013.4 lbs) fuel. My speed was ~M0.84. I thought that was pretty good going. Using 32% of fuel to travel 2100 nm gives the 707 a range of more than 6000nm. But... I actually had a pretty strong tail wind that helped a lot and so after taking that into account, I'd say a range of 5500nm should be reasonably close.

Mark

Yep, depends on the wind. I had up to 100knots headwind for about 2 hours in my 8 hour flight. Distance was 3800Nm. My speed was also arund 0.84. Maybe with a little less thrust and a speed of 0.80-0.82 you can easily do 4500Nm with full fuel tanks.